DE1420738A1 - Process for the aftertreatment of polymers - Google Patents

Description

Oberhaus en-Holt en, 3. 7. V1968 Ruhrchemie Aktiengesellschaft Eeht / Hü - H. 1560

.: P 14 20 736.6 (R 25 951 IVd / 39c)

Process for the aftertreatment of polymers

(Addition to patent. ... ... (patent application Ii 25 690 IVd / 39c [DAS 1 169 135])

In the patent (patent application R 25 690 IVd / 39c

[DAS 1 169 133J) is a process for the aftertreatment of polymers aliphatic olefins have been proposed. With the help of the procedure described there, it is possible to use polyolefins, in particular polyethylene and / or polypropylene with a bulk density, compared to the previous state-of-the-art technology by about a power of ten lower.

The working method of the main application consists in that the polymer, e.g. polyethylene and polypropylene, in a suitable solvent, e.g. tetramer propylene or in a solvent mixture dissolves under protective gas, possibly removing the undissolved constituents by hot filtration, cooling the solution lets the precipitated polymer through gently from the solvent.! Filtration or displacement separates and after intensive water washing dries. '.

Particularly suitable for treatment according to the specified procedure are polyolefins immediately after their manufacture. It has been found that one can post-treat polyolefins by dissolving in hydrocarbons or their mixtures in an amount of at most 50 g / liter of solvent using a Protective gas at temperatures between 80 and 175, if necessary Separation of undissolved constituents by hot filtration, allowing to precipitate in a manner known per se with cooling, liberation of the. Solvents in a gentle manner by filtration

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... ^ _; 809805/0765

Ruhrchemie Akfiengesellschaft 1420738

Oberhaüsen-Holten " ² ~ H 1560

Normal pressure or only a slight overpressure or underpressure or through. Displacement with oxygen-containing organic solvents and drying after repeated, single or multi-stage carried out Washing with water according to patent (patent application

H 25 690 IVcL / 39c [DAS 1 169 133]) works in such a way that the starting polyolefin the. in the suspension polymerization of the corresponding olefin still containing hydrocarbons Polyolefin filter residue, if necessary after removal of atactic Proportions and reduction of the ash content.

The swelling required for the production of polymers with low debris weight is as in the patent. ... ... (patent application R Z5 690 XVd / 39c [DAS 1 169 133J) by dissolving in higher molecular weight, aromatic and naphthenic hydrocarbons which are liquid at normal temperature, in particular by dissolving in aliphatic, straight or branched hydrocarbons with a carbon number of about 6 to 16, in particular 8 to 14, is achieved. The concentration should not exceed 50 g / liter of solvent, advantageously below 25 g / liter of solvent. The process of dissolving or swelling is expediently carried out at elevated temperatures between about 80 and 175, preferably 100 to 150 °. '.

The swollen and still considerable amounts of solvent containing]? i It is replaced and. is now in an organic liquid, e.g. acetone, tetrahydrofuran, slurried. This liquid should have a good dissolving power for the solvent, but a bad one for the polymer. She. should if possible do not form an azeotropic mixture with the solvent, or at most only contain small amounts in the boiling mixture, e.g. up to approx. 1%. . ■ ■ _ ■

Furthermore, the organic displacement liquid should, if possible, not form an azeotropic mixture with water, or at most boiling mixtures with only small amounts of water. After extensive displacement ^:

'BAD OBJGiNAL

- 3 809805/0765, ^^^^^^ --_

Ruhrchetme Aktiengesellschaft * ^ 2 07 SC

- 5 - ■■ - ■ - H 1560

Obefhausen ^ HoIten

of the solvent "removed to a content γ of less than 5 % , the displacer is removed by filtration and repeated washing with water. The residue, which has been washed out with water, is finally dried gently, with the use of faküim and one between -About -30 and 80 lying temperature. An advantage is ». '"

The obtained by this procedure. End products "have after previous screening. Bulk _densities} gßg'efeenenfalls the more lower than a power of ten are ¹ sprodukte than the Schüttgewiehte the respective output., During the work-up can be added to the polymer suitable inhibitors"

The end products obtained in this way are physiologically sound. Oils can therefore be used, among other things, for cosmetic purposes, for example for the manufacture of powders. niche purposes, flame spraying ,, vortex sintering ,, powdering of pesticides xmd use as filter material.

In the French patent specification -1 175 089 a process for the treatment of crystalline polyolefins is described, the aim of which is _{to remove foreign bodies t} low-molecular tm & non-crystalline: fractions and to win _{the polyolefin in the form of very small t spherical grains} Ixösung the polyolefins before ,, its precipitation UNAE by cool down _en% separation Slrocknung ". Since no special measures are used in these operations, the end product has the spherical Eorastruktxir jj © do. oh not a light, loose structure that weighs for the products according to the invention: a working method with venaind'ertem split; eharalcteristiBeh

was made with kris-fealliÄem SiCXL ₇ . and as a catalyst at a pressure of ρ kg / © m% of a BAP ORIGINAL

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Ruhrchemie Aktiengesellschaft 1420738 '

Oberhausen-Holten - 4 - -Y

! Temperature of 50 ° using hydrogenated tetramerpropy-. ien produced as a suspending agent. The crude polymer was used to remove the atactic compounds and reduce them the ash in the polymer in the heat with a mixture of Heptane-isopropanol-hydrochloric acid (91.5; -8: 0.5). Haeh Filtration was a portion of the residue in vacuo in a nitrogen atmosphere dried and after drying showed a bulk density of 265 g / liter and a knock weight of 330 g / liter. Another part of the polypropylene corresponds to about 20 g in. dry condition was still wet in 1500 ecm technical done (Boiling point 281 to 298 °). The mixture of polypropylene / cetane was heated to 130 ° with stirring. The polymer dissolved here the viscosity of the solution increased. A clear solution resulted. The heating and the stirrer were then turned off and allowed the solution to cool to room temperature. Here fell the polymer is voluminous. The cold solution was formalized filtered through a folded filter. From the moist residue the solvent was displaced by treatment with tetrahydrofuran, washed thoroughly with water and the polymer finally dried at 60 ° and 4-0 mm Hg under nitrogen protection '. The dried product was passed through a 1 mm wide mesh screen sifted. The end product had a bulk density of 27 g / liter and a knock weight of 39 g / liter.

BATH 8098Q5 / O765

Claims (1)

Ruhrchemie Aktiengesellschaft "14 2 07 3 B Pat eat entitlement Process for the aftertreatment of polyolefins by dissolving in Hydrocarbons or their mixtures in an amount of not more than 50 g / liter of solvent using a Protective gas at temperatures between 80 and 175, if necessary Separation * of undissolved components by hot filtration, Allowing to precipitate in a manner known per se with cooling and freeing of the solvents in a gentle manner by filtration at normal pressure or only a slight excess or Negative pressure or by displacement with organic organic compounds containing oxygen Solvent and drying after multiple, single or multi-stage washing with water according to the patent. (Patent application E 25 690 IVd / 39c [DAS 1 159 133]), thereby characterized in that one as: starting polyolefin in the Suspension polymerization of the corresponding olefin, Polyolefin filter residue still containing hydrocarbons, if necessary after removing atactic fractions and reducing the ash content. BAD OBfgffÄL 809805/07 65-; «..« 1 i _n »« rinnon lArt-TBi hh ». 2 No.t sentence3dea ?? change.ge.s. \ Jf, '4,9 «19S7i